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Abstract:

According to one embodiment, a card device includes an authentication
unit, a wireless communication unit, and a control unit. The
authentication unit performs an authentication process with an external
device via wired communication. The wireless communication unit performs
wireless communication with the external device. The control unit
controls the wireless communication unit to reduce radio waves radiated
from the wireless communication unit when the control unit detects that
the authentication process is being performed.

Claims:

1. A card device comprising: an authentication unit configured to perform
an authentication process with an external device via wired
communication; a wireless communication unit configured to perform
wireless communication via radio waves; and a control unit configured to
perform control to reduce radio waves radiated from the wireless
communication unit when the control unit detects that the authentication
process is being performed.

2. The card device according to claim 1, wherein when the control unit
detects that the authentication process is being performed, the control
unit controls the wireless communication unit to perform only a
connection process for connecting with a device to communicate with after
the authentication process but not to perform transmission and reception
of data.

3. The card device according to claim 1, wherein the control unit detects
whether the authentication process is being performed on the basis of a
state of a signal line used for the wired communication.

4. The card device according to claim 1, further comprising a power line
connected to the authentication unit and used for power supply to the
authentication unit, wherein the control unit detects whether the
authentication process is being performed on the basis of a state of the
power line.

5. The card device according to claim 1, wherein when performing the
authentication process, the authentication unit outputs, to the control
unit, a signal indicating that the authentication process is being
performed, and the control unit detects that the authentication process
is being performed when the control unit receives the signal.

Description:

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application is based upon and claims the benefit of priority
from Japanese Patent Application No. 2011-155893, filed on Jul. 14, 2011;
the entire contents of which are incorporated herein by reference.

FIELD

[0002] Embodiments described herein relate generally to a card device.

BACKGROUND

[0003] There has been conventionally known a card device that includes
mounted therein an authentication unit configured to perform an
authentication process with an external device via wired communication
and a wireless communication unit configured to perform wireless
communication to transmit and receive data.

[0004] For performing wireless communication, various electronic circuits
are driven, and electromagnetic noise (radio waves) is radiated from such
electronic circuits. Accordingly, if wireless communication is performed
while an authentication process is being performed, an error may occur in
the authentication result under the influence of electromagnetic noise
caused with the wireless communication. In particular, since the
authentication unit and the wireless communication unit are placed close
to each other in a small space of the card device, electromagnetic noise
radiated from the wireless communication unit has a significant impact on
the authentication process performed by the authentication unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]FIG. 1 is a diagram illustrating an exemplary schematic
configuration of a communication system according to a first embodiment;

[0006]FIG. 2 is a diagram illustrating an example of procedures for
stopping the operation of a wireless communication unit;

[0007]FIG. 3 is a diagram illustrating another example of procedures for
stopping the operation of the wireless communication unit;

[0008]FIG. 4 is a diagram illustrating an exemplary schematic
configuration of a communication system according to a second embodiment;

[0009]FIG. 5 is a diagram illustrating a modified example of a card
device according to the second embodiment; and

[0010]FIG. 6 is a diagram illustrating an exemplary configuration of a
card device according to a third embodiment.

DETAILED DESCRIPTION

[0011] According to one embodiment, a card device includes an
authentication unit, a wireless communication unit, and a control unit.
The authentication unit performs an authentication process with an
external, device via wired communication. The wireless communication unit
performs wireless communication with the external device. The control
unit controls the wireless communication unit to reduce radio waves
radiated from the wireless communication unit when the control unit
detects that the authentication process is being performed.

[0012] Various embodiments will be described below in detail with
reference to the accompanying drawings.

First Embodiment

[0013]FIG. 1 is a block diagram illustrating an exemplary schematic
configuration of a communication system 100 according to a first
embodiment. As illustrated in FIG. 1, the communication system 100
includes a portable device (equipment) 20 in which a card device 10 is
mounted and an external device 30. The device 20 may be of any type, and
examples thereof include a cellular phone handset and a card-type
terminal such as Suica (registered trademark). The external device 30 is
a device that can communicate with the device 20, and may be a server
device or a reader/writer capable of reading and writing data from/to the
card device 10 mounted in the device 20, for example. Although a case
where only one external device 30 capable of communicating with the
device 20 is used is illustrated in FIG. 1, any number of the external
devices 30 capable of communicating with the device 20 may be used, and
there may be two or more external devices 30, for example.

[0014] The card device 10 is an electronic device in which various
electronic components are mounted. As illustrated in FIG. 1, the card
device 10 includes an authentication unit 40, a wireless communication
unit 50 and a control unit 60. The authentication unit 40 performs an
authentication process with the external device 30 via wired
communication. The authentication unit 40 may be a secure element, for
example. As illustrated in FIG. 1, the authentication unit 40 is
connected to a device's wireless communication unit 21 provided in the
device 20 via a signal line 101 used for wired communication. The
device's wireless communication unit 21 wirelessly communicates with the
external device 30. Although not illustrated in detail, the device's
wireless communication unit 21 includes an electronic circuit, an antenna
and the like for performing wireless communication. Examples of the
antenna included in the device's wireless communication unit 21 include
an antenna for near field communication (NFC) and an antenna for 3G. The
antenna, however, is not limited thereto and any type of antenna can be
employed. When the antenna for NEC is employed, this part may be called a
contactless front end (CLF). In addition, the "authentication process"
described above refers to a process for authenticating the card device
10. In this embodiment, the authentication of the card device 10 is
performed by determining whether or not an identification number assigned
to the card device 10 matches a preregistered identification number.

[0015] More specifically, the external device 30 first transmits a request
signal requesting transmission of the identification number to the device
20. The request signal received by the device's wireless communication
unit 21 is transmitted to the authentication unit 40 via the signal line
101. The authentication unit 40 that has received the request signal
transmits the identification number assigned to the card device 10 to the
external device 30 via the signal line 101 and the device's wireless
communication unit 21. The authentication unit 40 may encrypt the
identification number before transmission, for example. The external
device 30 then decrypts the identification number transmitted from the
device 20 in response to the request signal and determines whether or not
the identification number obtained by the decrypt matches the
preregistered identification number to authenticate the card device 10
mounted in the device 20. Note that a process for receiving the request
signal by the authentication unit 40, a process for transmitting the
identification number by the authentication unit 40 and the like
correspond to the authentication process performed by the authentication
unit 40, but these are only one example of the authentication process.
Various known methods can be employed for the authentication process.

[0016] The wireless communication unit 50 performs wireless communication
via radio waves with the external device 30. Although not illustrated in
detail, the wireless communication unit 50 includes an electronic
circuit, an antenna and the like for performing wireless communication.

[0017] When the control unit 60 detects that the authentication process is
being performed by the authentication unit 40, the control unit 60
performs control to reduce the electromagnetic noise (radio waves)
radiated from the wireless communication unit 50. Detailed description
thereof will be given as follows. In this embodiment, the control unit 60
detects whether the authentication process is being performed on the
basis of the state of the signal line 101. Since the authentication unit
40 performs the authentication process with the external device 30 via
wired communication, a predetermined signal (a signal used for the
authentication process) is transmitted through the signal line 101 when
the authentication process is performed. More specifically, the current
flowing through the signal line 101 and the voltage level thereon change.
Since the current flowing through the signal line 101 and the voltage
level thereon do not change when wired communication is not performed
(that is, when the authentication process is not performed), it is
possible to detect that the authentication process is being performed by
detecting changes in the current flowing through the signal line 101 and
the voltage level thereon.

[0018] When the control unit 60 detects that the authentication process is
being performed as described above, the control unit 60 performs control
to reduce the electromagnetic noise radiated from the wireless
communication unit 50. For example, in this embodiment, when the control
unit 60 detects that the authentication process is being performed, the
control unit 60 controls the wireless communication unit 50 such that the
operation of the wireless communication unit 50 is stopped. As a result
of stopping the operation of the wireless communication unit 50, the
electromagnetic noise radiated from the wireless communication unit 50
can be mostly eliminated.

[0019] Alternatively, the control unit 60 may reduce the data transfer
rate of the wireless communication unit 50, for example. In general, the
power consumption at an electronic circuit tends to be larger as the data
transfer rate is higher, and the electromagnetic noise is also increased
with the increase in the data transfer rate. The electromagnetic noise
can therefore be reduced by lowering the data transfer rate.

[0020] Alternatively, the control unit 60 may make the wireless
communication unit 50 operate intermittently. As a result of making the
wireless communication unit 50 operate intermittently, there is a period
during which the wireless communication unit 50 is stopped. Thus, the
average amount of electromagnetic noise during a given period can be
reduced. If the wireless communication unit 50 also operates
intermittently during normal operation, the periods of the intermittent
operation may be made longer. As a result, the average amount of
electromagnetic noise during a given period can be reduced.

[0021] Alternatively, the control unit 60 may stop power supply to the
wireless communication unit 50, for example. As a result, the
electromagnetic noise radiated from the wireless communication unit 50
can be completely eliminated.

[0022] Next, procedures for stopping the operation of the wireless
communication unit 50 will be described. For example, as illustrated in
FIG. 2, when the control unit 60 detects that the authentication process
is being performed, the control unit 60 may control the wireless
communication unit 50 such that the operation of the wireless
communication unit 50 is stopped and may also control the wireless
communication unit 50 to transmit a stop request requesting to stop
operating to an external wireless communication unit of the external
device 30. Alternatively, with a configuration in which the external
device 30 includes an external authentication unit configured to perform
an authentication process and an external control unit configured to stop
the operation of the external wireless communication unit when it is
detected that an authentication process is being performed, for example,
when the control unit 60 detects that the authentication process is being
performed, the control unit 60 may control the wireless communication
unit 50 such that the operation of the wireless communication unit 50 is
stopped and the external control unit may control the external wireless
control unit such that the operation of the external wireless
communication unit is stopped as illustrated in FIG. 3.

[0023] For example, the control unit 60 may resume the operation of the
wireless communication unit 50 after elapse of a predetermined time
period from when the operation of the wireless communication unit 50 is
stopped. Alternatively, the control unit 60 may resume the operation of
the wireless communication unit 50 when the period during which the
authentication process being performed is not detected has lasted longer
than a predetermined length, for example.

[0024] While the procedures described above are those for stopping the
operation of the wireless communication unit 50, procedures for lowering
the data transfer rate of the wireless communication unit 50, for making
the wireless communication unit 50 operate intermittently or the like are
similar to those described above.

[0025] As described above, in this embodiment, when the control unit 60
detects that the authentication process is being performed, the control
unit 60 performs control to reduce the electromagnetic noise radiated
from the wireless communication unit 50. Therefore, an advantageous
effect that occurrence of errors in the authentication result under the
influence of the electromagnetic noise radiated from the wireless
communication unit 50 can be reduced is produced.

Second Embodiment

[0026] Next, a second embodiment will be described. The second embodiment
is different from the first embodiment in that the control unit 60
detects whether the authentication process is being performed on the
basis of the state of power supply to the authentication unit 40.
Detailed description thereof will be given below. Note that description
of parts that are the same as those in the first embodiment will not be
repeated as appropriate.

[0027]FIG. 4 is a block diagram illustrating an exemplary schematic
configuration of a communication system 100 according to the second
embodiment. In this example, power is supplied to the device 20 through
electromagnetic induction using lines of magnetic force generated by the
external device 30 when the device 20 is brought close to the external
device 30. More specifically, the device's wireless communication unit 21
includes a coil, and current is generated in the coil of the device's
wireless communication unit 21 when the lines of magnetic force emitted
from the external device 30 pass through the coil. The generated current
is rectified and smoothened by a power supply unit 22 provided in the
device 20, and supplied to the authentication unit 40 via a power line
102. After power is supplied to the authentication unit 40 and the
authentication unit 40 is activated, the authentication process is
started.

[0028] In this embodiment, the control unit 60 detects whether the
authentication process is being performed on the basis of the state of
the power line 102. More specifically, the control unit 60 can detect
whether or not power is being supplied to the power line 102 on the basis
of the current flowing through the power line 102 and the voltage level
thereon. When the control unit 60 detects that power is being supplied to
the power line 102, the control unit 60 detects that the authentication
process is being performed and performs control to reduce the
electromagnetic noise radiated from the wireless communication unit 50
similarly to the first embodiment.

[0029] As described above, since the authentication unit 40 starts the
authentication process after receiving power supply and being activated,
the authentication process is not yet performed at the time point when
the power supply to the power line 102 is started. Accordingly, the
control unit 60 preferably performs control to reduce the electromagnetic
noise radiated from the wireless communication unit 50 when the control
unit 60 detects that the power supply to the power line 102 is started.
As a result, noise radiated from the wireless communication unit 50 can
be reduced before the authentication process is started. There is thus an
advantage that occurrence of errors in the authentication result can be
reduced as compared to a configuration by which noise radiated from the
wireless communication unit 50 is reduced during the authentication
process.

[0030] In this embodiment, the authentication unit 40 performs the
authentication process after receiving power supply. The method of
detecting whether the authentication process is being performed on the
basis of the state of the power line 102 is therefore more advantageous
in that the authentication process being performed can be detected at an
earlier timing than the method of detecting whether the authentication
process is being performed on the basis of the state of the signal line
101.

[0031] Alternatively, a configuration in which a power source unit 70 that
includes a battery or the like is provided in the card device 10 as
illustrated in FIG. 5 may be used instead of power supply to the device
20 through electromagnetic induction as described above. Power from the
power source unit 70 is supplied to the authentication unit 40 via a
power line 71. The control unit 60 may control the power source unit 70
to supply power to the authentication unit 40 when the control unit 60
detects that a signal used for an authentication process is output to the
signal line 101. With such a configuration as well, the control unit 60
can detect that the authentication process is being performed by
detecting power supply to the power line 71.

[0032] With the configuration described above, occurrence of errors in the
authentication result under the influence of the electromagnetic noise
radiated from the wireless communication unit 50 can be reduced.

Third Embodiment

[0033] Next, a third embodiment will be described. The third embodiment is
different from the first embodiment in that the authentication unit 40
outputs a signal (hereinafter referred to as an "indicator signal")
indicating that the authentication process is being performed to the
control unit 60 when performing the authentication process, and that the
control unit 60 detects that the authentication process is being
performed when the indicator signal is received. Detailed description
thereof will be given below. Note that description of parts that are the
same as those in the first embodiment will not be repeated as
appropriate.

[0034]FIG. 6 is a diagram illustrating an exemplary configuration of a
card device 10 according to the third embodiment. As illustrated in FIG.
6, the difference from the first embodiment is that the card device 10
further includes an indicator line 103 connecting the authentication unit
40 and the control unit 60. In this embodiment, the authentication unit
40 outputs an indicator signal when performing the authentication
process. The indicator signal is transmitted to the control unit 60 via
the indicator line 103. The control unit 60 detects that the
authentication process is being performed when the control unit 60
receives the indicator signal, and performs control to reduce the
electromagnetic noise radiated from the wireless communication unit 50
similarly to the first embodiment. With this configuration as well,
occurrence of errors in the authentication result under the influence of
the electromagnetic noise radiated from the wireless communication unit
50 can be reduced.

[0035] Any type of the card device 10 may be used, and examples thereof
include an SD card, a micro SD card, a SIM card and an IC card.

[0036] Moreover, when the control unit 60 detects that the authentication
process is being performed, it may control the wireless communication
unit 50 to perform only a connection process for connecting with a device
to communicate with after the authentication process but not to perform
transmission/reception of data. The device to communicate with after the
authentication process may be the external device 30 for which the
authentication process is performed or may be another external device 30.
Note that, when data are to be transmitted/received through wireless
communication, the connection process needs to be performed before the
transmission/reception. The connection process, however, typically
requires a smaller amount of processing than transmission/reception of
data, and the amount of electromagnetic noise radiated from the wireless
communication unit 50 thus tends to be smaller. In addition, when data
are to be transmitted/received to/from a certain external device 30 after
completion of the authentication process, performing the connection
process for connecting with this external device 30 during the
authentication process allows the transmission/reception of data after
the authentication process to be started promptly. According to the
above-described configuration, advantageous effects that occurrence of
errors in the authentication result under the influence of the
electromagnetic noise radiated from the wireless communication unit 50
can be reduced and that transmission/reception of data after the
authentication process can be started promptly are therefore produced.
Note that the connection process for connecting with the external device
30 means a process for getting ready for communication with the external
device 30.

[0037] While certain embodiments have been described, these embodiments
have been presented by way of example only, and are not intended to limit
the scope of the inventions. Indeed, the novel embodiments described
herein may be embodied in a variety of other forms; furthermore, various
omissions, substitutions and changes in the form of the embodiments
described herein may be made without departing from the spirit of the
inventions. The accompanying claims and their equivalents are intended to
cover such forms or modifications as would fall within the scope and
spirit of the inventions.